[Max2075]

Originally Posted by m3bs

Hard to tell from those pics, but it looks like those rotors had enough wear that I would have replaced them long ago, even ignoring the heat checking. How many track days on them? What pads?

Agree, I always measure my rotor thickness when prepping for a track day and start bringing a spare set when getting close to min thickness.

[TrackClub]

Originally Posted by Max2075

Agree, I always measure my rotor thickness when prepping for a track day and start bringing a spare set when getting close to min thickness.

That's a first thing i had noticed (post #38).
The lip was huge, indicating massive amount of disc material has been used up already. Frankly, at such point heat checks are "academic" and even if there were no cracks, they should be off the car asap.

While reducing rotor size will reduce weight and as such may contribute to getting an extra tenth (maybe?), the brakes overall heat management will be adversely impacted - cooling, or not.

[TrackClub]

A good article on the subject, for those new to the hobby and a refresher for the rest of us:

https://www.essexparts.com/news-blog...ource=hs_email